A
width of a sphere indicated by fractions
of an inch. For example: ¼" ½", ¾".
When balls are ordered by this size
designation, it is the basis on which
the diameter tolerance per carton and
diameter tolerance per shipment applies.
This diameter indication is also known
as the "nominal diameter."

Basic
Diameter

A size
specified by a fraction plus a decimal.
For example ½" +.0003." When balls are
ordered by basic diameter, it is the
basis to which the diameter tolerance
per carton and diameter tolerance per
shipment applies.